A mobile radio communication system, communication apparatus applied in mobile radio communication system, and mobile radio communication method
The present invention relates to a mobile radio communication system in which UMTS (Universal Mobile Terrestrial communication System) and GSM (Group Specific Mobile) system coexist, communication apparatus applied in mobile radio communication system, and mobile radio communication method. More particularly this invention relates to a technology of observing the control channel of a GSM system that is another system in the mobile radio communication system by making use of an idle period.
In a CDMA cellular system, because the same carrier frequency is used repeatedly in every cell there is no need for handovers between frequencies within the same system. However, considering a case such as when existing systems are present together, there is a need for handovers between different carrier frequencies. Three points pertaining to detailed cases are described below.
As a first point, in a cell where there is considerable traffic, a separate carrier frequency is used to accommodate the increased number of subscribers, and a handover may be performed between those cells. As a second point, when an umbrella cell constitution is used, different frequencies are allocated to large and small cells, and handovers are performed between the cells. Then, as a third point, there are cases of handovers between a third generation system, such as a W (Wideband)-CDMA system, and a second-generation system, such as a current mobile telephone system.
When performing handovers in cases such as those mentioned above, it is necessary to detect the power of carriers at the different frequencies. To achieve this detection, the receiver need only have a structure capable of detecting two frequencies. However, this increases the size of the constitution of the receiver, or makes the constitution complicated.
Furthermore, two types of handover method may be considered: a mobile assisted handover (MAHO) and a network assisted handover (NAHO). Comparing the MAHO and NAHO methods, NAHO reduces the burden of the mobile device. However, it is necessary to synchronize the mobile device and the base station, whereby the constitution of the base station and the network becomes complicated and large in order to be capable of tracking each dedicated mobile device.
For such reasons, the realization of the MAHO method is more desirable, but to determine whether or not to handover, it is necessary to measure the strength of carriers of different frequencies at the mobile devices. However, a CDMA cellular system differs from a time division multiple access (TDMA) system used in a second generation, in that it uses ordinarily continuous transmission for both transmission/reception. In this continuous transmission/reception technique, unless receivers corresponding to two frequencies are prepared, it is necessary to stop the timing of the transmission or the reception and measure the other frequency.
There has been disclosed a technique relating to a compressed mode method, for time-compressing the transmission data in the normal mode and transmitting it in a short time, thereby creating some spare time which can be utilized to measure the other frequency carrier. As an example of this, there is Japan Patent Application National Publication (Laid-Open) (JP-A) No. 8-500475 xe2x80x9cNon-continuous Transmission for Seamless Handovers in DS-Mobile Radio Communications Systemsxe2x80x9d. This application discloses a method of realizing a compressed mode, wherein the spreading factor of the spreading code used is lowered to compress the transmission timing.
The method of realizing the compressed mode according to the above application will be explained below. FIG. 13 shows an example of transmissions in a normal mode and a compressed mode in a conventional CDMA system. In FIG. 13, the vertical axis represents transmission rate/transmission power, and the horizontal axis represents time. In the example of FIG. 13, the compressed mode transmission is inserted between normal transmission frames. In the transmission in the compressed mode, a non-transmission period is provided in the downlink frame, and can be set to a desired period of time (duration). This non-transmission period represents idle period during which the strength of the other frequency carrier is measured. In this way, slot transmission can be achieved by inserting the idle period between transmission of compressed mode frames.
In this type of compressed mode transmission, transmission power is increased in accordance with the time ratio between the idle period and the frame (compressed mode frame) transmission duration. Therefore, as shown in FIG. 13, the compressed mode frame is transmitted at a higher transmission power than the frame in normal transmission. Consequently, transmission quality can be maintained even in frame transmission in compressed mode.
Usually, between the GSM and GSM, different frequency component (control channel) is observed by using one observation period (no-transmission period) assigned in every one superframe. However, when a mobile radio communication system in which the UMTS and GSM systems coexist is considered, it requires operation for observing the frequency components between different systems, that is, from UMTS to GSM system. In this case, too, same as in the case of observation between GSM and GSM, an idle period for observing the frequency component of GSM is set in the superframe of the UMTS.
That is, for one frame of superframe in the UMTS, it is necessary to assign the observation period composed of the same number of idle slots as in the case of GSM-GSM observation. However, in the existing technology, due to restrictions in the error correction code and spreading factor for frame transmission, it is difficult to insert all observation period in one frame, and there are many other problems. Therefore, a technology for observing the frequency component of GSM system from the UMTS is expected in the future.
It is an object of the present invention to solve the problems mentioned above by providing a mobile radio communication system, communication apparatus applied in mobile radio communication system, and mobile radio communication method, capable of observing securely the frequency component of an another system from the UMTS even when the UMTS and the another system coexist, and suppressing deterioration of interleaving performance of compressed mode frame in such a case.
The mobile radio communication system according to one aspect of the invention is a mobile radio communication system comprising a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames being performed when the first communication system transmits the frames, wherein the specified idle period is at most half of the time of one frame that forms the first superframe and inserted in the first superframe at intervals of a specified number of frames, and wherein the frequency component of control data transmission channel of the second communication system is observed from the first communication system by making use of the idle period.
According to the above invention, when the first communication system and second communication system coexist, since the idle period for observing the frequency component of the second communication system is inserted at most in xc2xd time of one frame duration for composing one superframe of first communication system, at intervals of a specified number of frames, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
In the mobile radio communication system according to another aspect of the invention, wherein the first communication system is the UMTS that transmits frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and wherein the second communication system is an another system that transmits frames by using a second superframe of an equal transmission period as the first superframe of the UMTS.
According to the above invention, in a case where the UMTS and another system coexist, since the idle period for observing the frequency component of the another system is inserted at most in xc2xd time of one frame duration for composing one superframe of UMTS, at intervals of a specified number of frames, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the UMTS and another system coexist, the frequency component of the another system can be securely observed from the UMTS, and deterioration of interleaving performance of the compressed mode frame can be suppressed at this time. Besides, in the invention, the first superframe corresponds to the one UMTS superframe mentioned in an embodiment described later, the second superframe to the one GSM superframe, the third superframe to the one FCCH/SCH superframe, the user data transmission channel to the dedicated traffic channel, and the control data transmission channel to the common control channel, respectively.
In the mobile radio communication system according to another aspect of the invention, the interval of a specified number of frames is determined according to the difference in the transmission period between the UMTS and the another system.
According to the above invention, since the interval of a specified number of frames is determined by the difference in the transmission period between the UMTS and another system, the different frequency components can be observed completely depending on the difference in the transmission period.
In the mobile radio communication system according to another aspect of the invention, the specified idle period is placed in the center of the frame that is the unit of a superframe of the UMTS.
According to the above invention, since the idle period is placed in the center of the frame which is the unit of superframe of the UMTS, the interleaving effect can be obtained securely.
The mobile radio communication system according to another aspect of the invention is a mobile radio communication system comprising a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames is performed when the first communication system transmits the frames, wherein the specified idle period is at most half of the time of one frame that forms the first superframe and inserted in the first superframe at not necessarily regular intervals of a specified number of slots, and wherein the frequency component of control data transmission channel of the second communication system is observed from the first communication system by making use of the idle period.
According to the above invention, in the case where the first communication system and second communication system coexist, since the idle period for observing the frequency component of the second communication system is inserted at most in xc2xd time of one frame duration for composing one superframe of first communication system, at intervals of a specified number of slots, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
In the mobile radio communication system according to another aspect of the invention, wherein the first communication system is the UMTS that transmits frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and wherein the second communication system is an another system that transmits frames by using a second superframe of an equal transmission period as the first superframe of the UMTS.
According to the above invention, in the case where the UMTS and another system coexist, since the idle period for observing the frequency component of the another system is inserted at most in xc2xd time of one frame duration for composing one superframe of UMTS, at intervals of a specified number of slots, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the UMTS and another system coexist, the frequency component of the another system can be securely observed from the UMTS, and deterioration of interleaving performance of the compressed mode frame can be suppressed. Besides, according to the invention, the first superframe corresponds to the one UMTS superframe mentioned in the embodiment described later, the second superframe to the one GSM superframe, the third superframe to the one FCCH/SCH superframe, the user data transmission channel to the dedicated traffic channel, and the control data transmission channel to the common control channel, respectively.
In the mobile radio communication system according to another aspect of the invention, the interval of a specified number of slots is determined according to the difference in the transmission period between the UMTS and the another system.
According to the above invention, since the interval of a specified number of slots is determined by the difference in the transmission period between the UMTS and another system, the different frequency components can be observed completely depending on the difference in the transmission period.
In the mobile radio communication system according to another aspect of the invention, the plural numbers of the specified idle periods are placed in the UMTS superframe and the idle period may be differently set in each frame.
According to the above invention, since the plural idle periods in the superframe of the UMTS are placed separately in each frame, the necessary idle duration is held in one superframe.
In the mobile radio communication system according to another aspect of the invention, the total of the idle period is equal to the specified idle period provided for observing the frequency component of the another systems.
According to the above invention, since the total of the plural idle periods is equal to the specified idle period provided for observing the frequency component of the other systems, the total idle periods is equal to the observation duration of different frequencies between other systems can be held in one superframe.
In the mobile radio communication system according to another aspect of the invention, the frame in which the specified idle period is inserted is compressed and transmitted intermittently.
According to the above invention, since the frame in which the specified idle time is inserted is compressed and transmitted intermittently, a frame transmission of a high decodability is realized even when an idle period is inserted in one frame period.
In the mobile radio communication system according to another aspect of the invention, the compressed frame is generated by increasing the coding rate.
According to the above invention, since the compressed frame is generated by increasing the coding rate, the compression ratio is lowered, and the number of spreading codes of a shorter code length can be suppressed.
In the mobile radio communication system according to another aspect of the invention, the compressed frame is generated at a spreading factor that is the same as the spreading factor at which a frame that do not contain the specified idle period is generated.
According to the above invention, since the compressed frame is generated at a same spreading factor as another frame in which the specified idle period is not inserted, the interference and noise resistant characteristic to the compressed frame is assured.
The communication apparatus applied in a mobile radio communication system according to another aspect of the invention is a communication apparatus applied in a mobile radio communication system comprising a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames being performed when the first communication system transmits the frames, frames being transmitted continuously in the case of normal mode, and compressed frames being transmitted intermittently in the case of compressed mode, wherein the communication apparatus comprises a control unit for inserting a specified idle period, during the compressed mode, in the first superframe, having a duration that is at most portion of one frame that forms the first superframe, and at intervals of a specified number of frames, and wherein the frequency component of control data transmission channel of the second communication system is observed from the first communication system by making use of the specified idle period inserted by the control unit.
According to the above invention, in the case where the first communication system and second communication system coexist, since it is controlled so that the idle period for observing the frequency component of the second communication system is inserted at most in xc2xd time of one frame duration for composing superframe in the superframe of the first communication system, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, wherein the first communication system is the UMTS that transmits frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and wherein the second communication system is an another system that transmits frames by using a second superframe of an equal transmission period as the first superframe of the UMTS.
According to the above invention, in the case where the UMTS and another system coexist, since the idle period for observing the frequency component of the another system is inserted at most in xc2xd time of one frame duration for composing one superframe of UMTS, at intervals of a specified number of frames, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the UMTS and another system coexist, the frequency component of the another system can be securely observed from the UMTS, and deterioration of interleaving performance of the compressed mode frame can be suppressed. Besides, in the invention, the first superframe corresponds to the one UMTS superframe mentioned in the embodiment described later, the second superframe to the one GSM superframe, the third superframe to the one FCCH/SCH superframe, the user data transmission channel to the dedicated traffic channel, and the control data transmission channel to the common control channel, respectively.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit determines the interval of a specified number of frames according to the difference in the transmission period between the UMTS and the another system.
According to the above invention, since the interval of a specified number of frames is determined by the difference in the transmission period between the UMTS and another system at the time of controlling, the different frequency components can be observed completely depending on the difference in the transmission period.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit places the specified idle period in the center of the frame that is the unit of superframe of the UMTS.
According to the above invention, since the specified idle period is placed in the center of the frame which is the unit of superframe of the UMTS at the time of controlling, the interleaving effect may be obtained securely.
The communication apparatus applied in a mobile radio communication system in a different aspect of the invention is a communication apparatus applied in a mobile radio communication system comprising a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel, on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames being performed when the first communication system transmits the frames, frames being transmitted continuously in the case of normal mode, and compressed frames being transmitted intermittently in the case of compressed mode, wherein the communication apparatus comprises a control unit for inserting a specified idle period, during the compressed mode, in the first superframe, having a duration that is at most portion of one frame that forms the first superframe, and at not necessarily regular intervals of a specified number of slots, and wherein the frequency component of control data transmission channel of the second communication system is observed from the first communication system by making use of the specified idle period inserted by the control unit.
According to the above invention, in the case where the first communication system and second communication system coexist, since it is controlled so that the idle period for observing the frequency component of the second communication system is inserted at most in xc2xd time of one frame duration for composing superframe in the superframe of the first communication system and at an interval of a specified number of slots, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore, even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the first communication system is the UMTS that transmits frames by using wherein the first communication system is the UMTS that transmits frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and wherein the second communication system is an another system that transmits frames by using a second superframe of an equal transmission period as the first superframe of the UMTS.
According to the above invention, in the case where the UMTS and another system coexist, since the idle period for observing the frequency component of the another system is inserted at most in xc2xd time of one frame duration for composing one superframe of UMTS, at intervals of a specified number of slots, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied, and therefore even when the UMTS and another system coexist, the frequency component of the another system can be securely observed from the UMTS, and deterioration of interleaving performance of the compressed mode frame can be suppressed. Besides, according to the invention, the first superframe corresponds to the one UMTS superframe mentioned in the embodiment described later, the second superframe to the one GSM superframe, the third superframe to the one FCCH/SCH superframe, the user data transmission channel to the dedicated traffic channel, and the control data transmission channel to the common control channel, respectively.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit determines the interval of a specified number of frames according to the difference in the transmission period between the UMTS and the another system.
According to the above invention, since the interval of a specified number of slots is determined by the difference in the transmission period between the UMTS and another system at the time of controlling, different frequency components can be observed completely depending on the difference in the transmission period.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit provides the specified idle period at many places in the UMTS superframe and the sets each idle period differently in each frame.
According to the above invention, since plural idle periods are disposed in each frame in the superframe of the UMTS at the time of controlling, a necessary idle duration can be held in one superframe.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit sets the idle period in such a way that the total of then is equal to the specified idle duration provided for observing the frequency component between the another systems.
According to the above invention, since the total of the plural idle periods is set equal to the specified idle duration provided for observing the frequency component between the other systems at the time of controlling, an idle duration equal to observation of different frequencies between other systems can be held in one superframe.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit increases the coding rate when generating the compressed frame.
According to the above invention, since the compressed frame is generated by increasing the coding rate at the time of controlling, the compression ratio is lowered, and the number of spreading codes of a shorter code length can be suppressed.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit sets a spreading factor when generating the compressed mode frame that is the same as the spreading factor at which a frame that do not contain the specified idle period is generated.
According to the above invention, since the compressed frame is generated at a same spreading factor as another frame in which the specified idle period is not inserted at the time of controlling, the interference and noise resistant characteristic of the compressed frame is assured.
In the communication apparatus applied in a mobile radio communication system according to another aspect of the invention, the control unit increases the average transmission power during the compressed mode.
According to the above invention, since the average transmission power is increased in the compressed mode at the time of controlling, the characteristic deterioration may be suppressed to a minimum limit.
The mobile radio communication method according to another aspect of the invention is a mobile radio communication method, applied in a mobile radio communication system having, a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames being performed when the first communication system transmits the frames, frames being transmitted continuously in the case of normal mode, and compressed frames being transmitted intermittently in the case of compressed mode, the method comprising a first step of compressing frames to be transmitted intermittently during the compressed mode, and a second step of transmitting the frames compressed in the first step intermittently by inserting a specified idle period, in the first superframe, having a duration that is at most portion of one frame that forms the first superframe, and at intervals of a specified number of frames determined by the relation of the frame structure between the first communication system and the second communication system, and the frequency component of control data transmission channel of the second communication system being observed from the first communication system by making use of the specified idle period inserted in the second step.
According to the above invention, by compressing the frames transmitted intermittently at the time of compressed mode, and inserting an idle period for observing the frequency component of the second communication system at most in xc2xd time of one frame duration for composing the superframe of the first communication system in the superframe of the first communication system and at an interval of a specified number of frames determined by the relation of the frame structure between the first communication system and second communication system, since the step for transmitting intermittently the compressed frames is set up, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
The mobile radio communication method according to another aspect of the invention is a mobile radio communication method, applied in a mobile radio communication system having, a first communication system employing a code division multiple access method of transmitting frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and a second communication system for observing frequency component of control data transmission channel by making use of a specified idle period, the specified idle period being inserted in a second superframe for downlink user data transmission channel on the basis of the difference between the number of frames of integer multiple of second superframe expressing a frame transmission period in user data transmission channel and the number of frames of third superframe expressing a frame transmission period in control data transmission channel, error correction and interleaving of frames being performed when the first communication system transmits the frames, frames being transmitted continuously in the case of normal ode, and compressed frames being transmitted intermittently in the case of compressed mode, the method comprising a first step of compressing frames to be transmitted intermittently during the compressed mode, and a second step of transmitting the frames compressed in the first step intermittently by inserting a specified idle period, in the first superframe, having a duration that is at most half of one frame that forms the first superframe, and at intervals of a specified number of slots determined by the relation of the frame structure between the first communication system and the second communication system, and the frequency component of control data transmission channel of the second communication system being observed from the first communication system by making use of the specified idle period inserted in the second step.
According to the above invention, by compressing the frames transmitted intermittently at the time of compressed mode, and inserting an idle period for observing the frequency component of the second communication system at most in xc2xd time of one frame duration for composing the superframe of the first communication system in the superframe of the first communication system and at an interval of a specified number of slots determined by the relation of the frame structure between the first communication system and second communication system, since the step for transmitting intermittently the compressed frames is set up, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied. Therefore even when the first communication system and second communication system coexist, the frequency component of the second communication system can be securely observed from the first communication system. Further, deterioration of interleaving performance of the compressed mode frame during such observation can be suppressed.
In the mobile radio communication method in another aspect of the invention, the first communication system is the UMTS that transmits frames by using a first superframe expressing a frame transmission period, wherein the first communication system is the UMTS that transmits frames by using a first superframe which is formed of a plural frames and which expresses a frame transmission period, and wherein the second communication system is an another system that transmits frames by using a second superframe of an equal transmission period as the first superframe of the UMTS.
According to the above invention, in particular, in the case where the UMTS and another system coexist, since the idle period for observing the frequency component of the another system is inserted at most in xc2xd time of one frame duration for composing one superframe of UMTS, at intervals of a specified number of frames or at an interval of a specified number of slots, it is not required to observe the frequency component by one observation in one superframe, and the restrictions in frame transmission such as error correction code and spreading factor can be satisfied, and therefore even when the UMTS and another system coexist, the frequency component of the another system can be securely observed from the UMTS, and deterioration of interleaving performance of the compressed mode frame can be suppressed. Besides, according to the invention, the first superframe corresponds to the one UMTS superframe mentioned in the embodiment described later, the second superframe to the one GSM superframe, the third superframe to the one FCCH/SCH superframe, the user data transmission channel to the dedicated traffic channel, and the control data transmission channel to the common control channel, respectively.
In the mobile radio communication method according to another aspect of the invention, the compressed frames are generated in the first step by increasing the coding rate.
According to the above invention, since the compressed frame is generated by increasing the coding rate at this step, the compression ratio is lowered, and the number of spreading codes of a shorter code length can be suppressed.
In the mobile radio communication method according to another aspect of the invention, the compressed frame is generated in the first step at a spreading factor that is the same as the spreading factor at which a frame that do not contain the specified idle period is generated.
According to the above invention, since the compressed frame is generated at a same spreading factor as another frame in which the specified idle period is not inserted at this step, the interference and noise resistant characteristic to the compressed frame is assured.
In the mobile radio communication method according to another aspect of the invention, average transmission power is increased in the second step during the compressed mode.
According to the above invention, since the average transmission power is increased in the compressed mode at this step, the characteristic deterioration may be suppressed to a minimum limit.